Method of controlling orientation of domains in block copolymer films

ABSTRACT

A method of orienting microphase-separated domains is disclosed, comprising applying a composition comprising an orientation control component, and a block copolymer assembly component comprising a block copolymer having at least two microphase-separated domains in which the orientation control component is substantially immiscible with the block copolymer assembly component upon forming a film; and forming a compositionally vertically segregated film on the surface of the substrate from the composition. The orientation control component and block copolymer segregate during film forming to form the compositionally vertically-segregated film on the surface of a substrate, where the orientation control component is enriched adjacent to the surface of the compositionally segregated film adjacent to the surface of the substrate, and the block copolymer assembly is enriched at an air-surface interface.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a CONTINUATION application of U.S. application Ser.No. 12/060,516, filed Apr. 1, 2008, which is a Continuation Applicationof U.S. application Ser. No. 12/013,138, (now U.S. Pat. No. 7,763,319,issued Jul. 27, 2010), the disclosure of which is incorporated byreference herein its entirety.

TRADEMARKS

IBM® is a registered trademark of International Business MachinesCorporation, Armonk, N.Y., U.S.A. Other names used herein may beregistered trademarks, trademarks or product names of InternationalBusiness Machines Corporation or other companies.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method of orienting microphase-separateddomains of block copolymers with respect to a substrate, andspecifically to a composition and method of using the composition toorient microphase-separated domains of block copolymers with respect toa substrate.

2. Description of Background

Block copolymers films can be used as a part of an assembly system, inwhich nanoscale features form when blocks of the block copolymers phaseseparate into microdomains (also referred to herein as“microphase-separated domains” or “domains”) to reduce the total freeenergy. Such thin films of block copolymers provide features havingspatial chemical contrast at nanometer-scale, and consequently by theirability to generate these periodic nanoscale structures have been usedas a low-cost material for nanopatterning. One problem in blockcopolymer patterning is with respect to controlling the orientation ofthe assembled microdomains. For example, lamellae forming blockcopolymers (FIG. 1A) can align their domains parallel to the plane ofthe substrate on which they are coated (FIG. 1B), or perpendicularly tothe substrate surface (FIG. 1C). When lamellae form parallel to theplane of the substrate, one lamellar phase forms a first layer at thesurface of the substrate (in the x-y plane of the substrate), andanother lamellar phase forms a second, parallel layer on the firstlayer, so that no patterns of microdomains are obtained when viewing thefilm along the perpendicular (z) axis; however, when lamellae formperpendicular to the surface, the perpendicularly oriented lamellaeprovide nanoscale line patterns. Without external orientation control,thin films of block copolymers tend to organize into randomly orientednanostructures or undesired morphologies, which are of no use fornanopatterning because of the random nature of the features.

Orientation of block copolymer microdomains can be obtained by pairingthe assembly process of the layer of block copolymer, with an externalorientation biasing method such as use of a mechanical flow field,electric field, temperature gradient, or by the influence of surfaceinteraction on the block copolymer by a surface modification layer. Ofthese, use of a surface modification layer for orientation control isrelatively straightforward to integrate into a spin-casting or otherfilm-forming manufacturing process, and is therefore desirable. Randomcopolymer brushes, thermally cross-linked random copolymers, andassembled monolayers have each been used as the basis of an orientationcontrol layer to induce preferential orientation in block copolymer thinfilms.

An orientation control layer can present a neutral or a non-neutralsurface to block copolymers. The orientation control layer can have asurface that is preferentially wetted by a particular block of the blockcopolymer; such a surface is considered not to be neutral. The surfaceof neutral orientation control layer is wettable by more than one blockin the block copolymer. Therefore, on a neutral orientation controllayer, the cylinder-forming and lamellae-forming block copolymer formlaterally microphase-separate domains which orient perpendicularly tothe neutral orientation control layer. Typical neutral orientationcontrol layers have been prepared by casting a film of a randomcopolymer comprising the monomers of each block. For example, a neutralorientation control layer for the poly(styrene-b-methyl methacrylate)diblock copolymer can be made from a random copolymer of styrene andmethylmethacrylate.

While surface modification methods, particularly use of orientationcontrol layers, can be integrated into the manufacturing process,additional processing steps are necessary, including dispense, spin,bake, or rinsing steps, to apply the orientation control layer prior tocasting block copolymer thin films, the sum of which extend processcycle time and increases the complexity of the processing sequence.Longer processes (i.e., those having more processing steps) are notgenerally desirable, as such processes introduce more opportunity forintroduction of coating defects, reducing overall device yield andincreasing the cycle time for producing devices.

SUMMARY OF THE INVENTION

The shortcomings of the prior art are overcome and additional advantagesare provided through the provision of a simple and compatible method fororientation control for successful implementation of block copolymerpatterning of a composition.

In an embodiment, a composition comprises an orientation controlcomponent, a block copolymer assembly component comprising a blockcopolymer that forms microphase-separated domains upon forming a film,and a solvent in which both orientation control component and blockcopolymer assembly component are soluble, wherein the orientationcontrol component is segregated from the block copolymer assemblycomponent upon forming a film from the composition, and the orientationcontrol component has an affinity for the surface of a substrate that isgreater than the block copolymer assembly component's affinity for thesurface of the substrate such that the orientation control component isenriched at a surface of the substrate upon forming the film.

In another embodiment, a method comprises applying the composition to asurface of a substrate; and forming a compositionallyvertically-segregated film on the surface of the substrate from thecomposition, wherein the orientation control component is enrichedadjacent to the surface of the substrate, the block copolymer assemblycomponent is enriched at an air-film interface, and the different blocksof the block copolymer form laterally-segregated microphase-separateddomains.

In another embodiment, a method comprises forming a film of a blockcopolymer assembly having microphase-separated domains with a desiredorientation, from a composition comprising an orientation controlcomponent, and a block copolymer assembly component that formsmicrophase-separated domains upon forming a film, and a solvent in whichboth the orientation control component and block copolymer assemblycomponent are soluble, wherein the orientation control component isvertically segregated from the block copolymer assembly component uponforming a film from the composition, and the orientation controlcomponent has an affinity for the surface of a substrate that is greaterthan the block copolymer assembly component's affinity for the surfaceof the substrate, such that the orientation control component isenriched at the surface of the substrate upon forming the film.

In another embodiment, a method of forming a block copolymer assemblycomprising oriented microphase-separated block copolymer domains in acompositionally vertically-segregated film comprises: applying acomposition to a surface of a substrate, the composition comprising anorientation control component comprising a homopolymer or copolymer ofepoxycyclopentadienyl (meth)acrylate, and a block copolymer assemblycomponent comprising a diblock copolymer or triblock copolymer ofstyrene and methyl methacrylate, wherein the orientation controlcomponent is vertically segregated from the block copolymer assemblycomponent upon forming a film from the composition, and the orientationcontrol component has an affinity for the surface of a substrate that isgreater than the block copolymer assembly component's affinity for thesurface of the substrate; forming a layer of the composition on thesurface of the substrate; and baking the composition, wherein theorientation control component and block copolymer assembly componentsegregate to form a compositionally vertically-segregated film on thesurface of the substrate during forming, wherein the orientation controlcomponent is enriched at a film-substrate interface, and the blockcopolymer is enriched at an air-film interface.

A film prepared by the method, and a topographical pattern formed byselectively removing a microphase-separated domain of the blockcopolymer assembly are also disclosed.

Additional features and advantages are realized through the techniquesof the present invention. Other embodiments and aspects of the inventionare described in detail herein and are considered a part of the claimedinvention. For a better understanding of the invention with advantagesand features, refer to the description and to the drawings.

TECHNICAL EFFECTS

As a result of the summarized invention, technically we have achieved acompositionally segregated film which provides for a simultaneousformation of an orientation control layer at the surface of a substrate,and microphase-separated block copolymer layer opposite the surface ofthe substrate. The method as disclosed allows for the assemblingpreparation of nanoscale structural features using a single depositionstep, thereby reducing processing and cycle time in the fabrication ofsuch structures, and eliminating the need for the logistical problems ofacquiring, storage, and dispensing of multiple components.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The subject matter which is regarded as the invention is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 illustrates schematic representations of: (A) lamellae-formingblock copolymers in which different blocks are depicted with differentfill patterns; (B) a block copolymer thin film with lamellar domainsoriented parallel to the substrate; (C) a block copolymer thin film withlamellae domains oriented perpendicular to the substrates; (D) an atomicforce microscopy (AFM) image of an exemplary lamellae-formingpoly(styrene-b-methyl methacrylate) (abbreviated “PS-b-PMMA”) filmformed on a silicon substrate without orientation control;

FIG. 2 illustrates schematic representations of: (A) a conventionalorientation control method, and (B) a one-step orientation controlmethod for microphase orientation control in block copolymer thin films;

FIG. 3 illustrates (A) an AFM image of an exemplary perpendicularlyoriented lamellar PS-b-PMMA film made with a “one-step” orientationcontrol process using poly(epoxydicyclopentadienyl methacrylate) as anorientation control component; (B) a scanning electron micrograph (SEM)image of a cross-section of perpendicular PS lamellae (after removal ofPMMA by a selective etch) on the top of orientation control layer of theexemplary film described in (A); (C) an AFM image of perpendicularlyoriented cylinders in a PS-b-PMMA film made from a single spin and bakestep of a composition of PS-b-PMMA and poly(epoxydicyclopentadienylmethacrylate) as the orientation control component;

FIG. 4 illustrates four AFM images corresponding to exemplaryperpendicularly oriented PS-b-PMMA lamellae made by a singlespin-and-bake step, for four exemplary solutions having different weightratios of PS-b-PMMA (abbreviated as “BCP” for “block copolymer” in thefigure) and poly(styrene-ran-epoxydicyclopentadienyl methacrylate); and

FIG. 5 illustrates the structures of (A) poly(epoxydicyclopentadienylmethacrylate) and (B) poly(styrene-ran-epoxydicyclopentadienylmethacrylate).

The detailed description explains the preferred embodiments of theinvention, together with advantages and features, by way of example withreference to the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein is a “one-step” method for generating a film (alsobroadly referred to herein as a compositionally segregated film)comprising an orientation control layer or region and a thin film ofblock copolymer with controlled orientation of the microdomains, by asingle spin-and-bake step. The orientation control layer or regiondesirably comprises orientation control components that can crosslinkduring subsequent processing.

Unexpectedly, it has been found that combining the microdomain-formingblock copolymer with the orientation control component provides a singlefilm forming composition which, when coated on a substrate in afilm-forming process will, when the block copolymer and orientationcontrol component vertically segregate, form an orientation controlregion or layer of the orientation control component at the coatedsurface, and a microdomain-forming region or layer of the blockcopolymer at the surface-air interface opposite the coated surface ofthe substrate.

As disclosed herein, “immiscible” and “immiscibility” of these polymercomponents refers to the propensity of the two polymer components (i.e.,the block copolymer and the orientation control component) to phasesegregate due to an unfavorable free energy of mixing of the polymers.Also as used herein, “segregate” refers to the propensity of the blockcopolymer and the orientation control component to separate during thefilm forming process. “Vertical” refers to the direction of orientationorthogonal to the plane of the substrate, and “vertically segregated” isexemplified by the segregation of components (such as the orientationcontrol component and block copolymer) to form stratified layers or agradient. Similarly, “lateral” refers to the direction of the x-y planeof the substrate and “laterally segregated” is exemplified by theformation of different, microphase-separate domains formed adjacent toone another on the surface of the substrate.

With a neutral orientation control layer, the block copolymer domainsform at the interface and extend vertically from the surface of thesubstrate. Typical exemplary methods of film forming include but are notlimited to spin coating, spray coating, doctor blading, dip coating,optionally followed by baking. “Baking”, is a general process whereinthe temperature of the substrate and coated layers thereon is raisedabove ambient temperature to effect additional processing of the filmsuch as removal of volatile compounds, reducing the film volume, furtherorienting or diffusing components in the film, or effecting furtherchemical reactions within the film. “Annealing” is a process used toremove defects and stresses in the film and can be accomplished by anumber of methods including, but not limited to, thermal annealing,solvent vapor annealing, zone annealing, annealing under externalelectrical, magnetic, or field, or the like. Thermal annealing,sometimes referred to as “thermal curing” can be a baking process forremoving defects and improving the ordering of block copolymer domainsin the layer of the block copolymer assembly, and generally involvesheating at elevated temperature (e.g., above the glass transitiontemperature of the block copolymer), typically for a period of time(several minutes to several days) at or near the end of the film-formingprocess. Annealing, where performed, typically is used to improveordering of the laterally separated microdomains.

By the nature of the segregation mechanism, upon forming a film with thefilm-forming composition on a substrate in this one-step method, acompositionally segregated film is generated with the orientationcontrol component enriched to form a region or layer at the surface ofthe substrate being coated, and with the block copolymer enriched at theair interface to form a block copolymer enriched region or layer at thetop of the orientation control component-enriched region or layer. Themethod provides for a preferred, controllable orientation ofmicrodomains in a variety of block copolymer thin films, includingarrangement of the microdomains to selectively provide parallel orperpendicularly oriented lamellae or cylinders in diblock copolymers,and more complicated structures including tri-block and multi-blockcopolymers. The method can be used to prepare oriented block copolymermicrodomains on a variety of substrates, provided that the orientationcontrol components segregate to the substrate interfaces and the blockcopolymer segregates to the surface of the orientation control region,disposed opposite the substrate.

The “microdomain”, sometimes referred to as “microphase-separateddomain” or simply as “domain”, is a structural feature in a blockcopolymer film wherein blocks of the block copolymer aggregate to formregular periodic structures, with the adjustable dimensions of thestructures tuned according to the number of monomeric repeating units ofthe block forming the domain, the functionality of the monomers in thedomain, and the arrangement of monomers in the block including sequenceand/or stereochemistry (e.g., atactic, isotactic, or syndiotacticmonomer arrangements; or chiral monomers).

Where “layer” is used, a discrete, substantially compositionallydistinct phase with a distinct interface adjacent to anothersubstantially compositionally distinct phase is meant. Where “region” isused, a phase that contains more of one component (such as anorientation control component) than another component (such as a blockcopolymer) is meant. Regions need not have a discrete interface, but maybe characterized compositionally, or based on performance properties. Aregion can thus have a gradient composition which varies from one sideof the film to the other. Where the compositional gradient isperpendicular to the plane of the substrate, the gradient can be said tobe “vertical” or oriented “vertically”. The formation of the verticallysegregated film occurs during film-forming, which can comprise insequence coating the film forming composition to provide the film,baking the film, and where desired, annealing the film. Verticalsegregation of the orientation control components and block copolymerassembly components occurs during one or more of these operations. Insome embodiments, the vertical phase segregation can occur at either thecoating or baking steps; in other embodiments, vertical segregationoccurs during both the coating and baking steps. Where the phasesegregation occurs during the coating step, the relative immiscibilityof the components with each other and/or with a common solvent canselectively deposit the orientation control layer components on thesubstrate, followed by depositing of the block copolymer assemblycomponents. Alternatively, or in addition, baking can separate thesecomponents where sufficient mobility of the components in the matrixoccurs, such as for example where solvent is present in the coated filmand/or where the components are mobile under the conditions of bake, forexample where baking takes place at a temperature higher than the Tg ofthe orientation control components and/or block copolymer assemblycomponents. Further, additional vertical segregation can occur byannealing, during which the rearrangement of the components also resultsin removal of coating defects. In a specific embodiment, the filmforming comprises coating by a spin-casting method, and baking.

In an embodiment, a vertically segregated two-layer film can be formed.In another embodiment, a vertically segregated multilayer film havingmore than two discrete layers can be formed. In another embodiment, avertically segregated gradient film is formed from at least two primarycomponents, in which the gradient film composition as determinedvertically from the surface of the substrate can vary from 100% oforientation control component at the film-substrate interface to 100% ofblock copolymer assembly component at the air-surface interface. In thisway, the gradient is vertically oriented.

By the disclosed method, during forming of the compositionallyvertically-segregated film, the film-forming composition can segregateas follows: (i) In one embodiment, a two layer film is formed, having anorientation control layer disposed on a surface of the substrate, and ablock copolymer assembly layer disposed on a surface of the orientationcontrol layer opposite the substrate, where the orientation controlcomponents and block copolymer assembly components are fully segregated.(ii) In another embodiment, a gradient film is formed wherein theorientation control component is enriched adjacent to the surface of thesubstrate, the block copolymer is enriched in the gradient film at asurface opposite the surface of the substrate, and the region of thefilm in between the surfaces comprises an admixture of the orientationcontrol component and the block copolymer assembly component(s).

A complete separation of the orientation control component and the blockcopolymer assembly component need not occur during segregating, so longas the block copolymer assembly can form microdomains to generate usefulpatterns. In an embodiment, the portion of the film containing theorientation control component can typically have a thickness of about 1nm to about 1,000 nm, which can vary depending on the particularcompositional and processing parameters selected.

In a conventional scheme (FIG. 2A), a block copolymer thin film withpreferred microphase separated domain orientation is created by twoseparate process steps. In FIG. 2A, the orientation control layer isfirst applied to a substrate surface with coating, baking and optionalrinsing processes to provide a neutral surface which does not dissolvein any subsequent film forming process conducted thereon. The film ofthe block copolymer assembly is subsequently formed from a compositioncontaining a block copolymer and any desired additives applied to thesurface of the pre-made orientation control layer opposite the substratesurface, and baked to form block copolymer domains with preferredorientation. In this way, the conventional scheme requires two filmforming processes, such as sequential spin-cast then bake processes, tocreate block copolymer thin films of preferred orientation.

FIG. 2B illustrates an embodiment of the method disclosed herein, inwhich an exemplary two-layer film stack including the layer comprisingthe block copolymer assembly and the orientation control layer is formin a single spin-cast then bake step. Vertical segregation of the blockcopolymer assembly components and orientation control componentscreates, in the embodiment illustrated, the two-layer film where theblock copolymer assembly components segregate to form top layer (i.e.,the exposed surface layer) and the orientation control componentssegregate to the substrate interface to form the bottom layer (i.e., thelayer disposed on the surface of the substrate). The orientation controllayer directs the phase segregation of block copolymer assemblycomponents to form the preferred orientation of the block copolymerassembly layer. As shown in FIG. 2B, the neutral orientation controllayer provides a neutral surface to allow more than one domain of theblock copolymer assembly to be present at the surface interface. Inaddition to providing a neutral interface, the orientation controlcomponents are able to dissolve in the same casting solvent as the blockcopolymers, and segregate from the block copolymers to form a layer orregion to induce the preferred orientation in the two-layer, multilayer,or gradient structures.

The method proposed in this invention advantageously reduces by at leasthalf the number of process steps needed to generate a block copolymerthin film with preferred orientation. This method can also considerablyshorten the process time. Neutral orientation control underlayers havebeen demonstrated by Hawker and Russell [P. Mansky, Y. Liu, E. Huang, T.P. Russell, and C. Hawker, “Controlling polymer surface interaction withrandom copolymer brushes”, Science, vol. 275, p. 1458, (1997); Du YeolRyu, Kyusoon Shin, Eric Drockenmuller, Craig J. Hawker, and Thomas P.Russell, “A generalized approach to modification of a solid surface,”Science, vol. 308, p. 236, (2005)] and Gopalan [Eungnak Han, Insik In,Sang-Min Park, Young-Hye La, Yao Wang, Paul F. Nealey, and PadmaGopalan, “Photopatternable imaging layers for controlling blockcopolymer micro domain orientation”, Advanced Materials, vol. 19, p.4448 (2007)]. However, forming methods for these prior art orientationcontrol underlayers require time periods ranging from minutes to hoursto attach the neutral underlayer components to the substrate to achievethe desired surface neutrality, and the formation of some of theseunderlayers further requires an additional rinse step to removeunattached neutral underlayer component materials, adding to the time,number of steps, and overall cost of the methods.

Thus, the film-forming composition used to provide the film (i.e., theorientation control layer and block copolymer assembly layer) comprisesat least 1) the orientation control component, 2) a block copolymerassembly component comprising a block copolymer which can assemble toform microphase-separated domains in the film, and 3) a solvent in whichboth orientation control component and block copolymer assemblycomponent are soluble. These components are further describedhereinbelow.

In an embodiment, the orientation control component comprises anepoxy-containing polymer that can be crosslinked by application of heatand/or a catalyst. The epoxy-containing polymer is desirably thepolymerization product of an epoxy-containing monomer, but can be anyepoxy-modified polymer or resin provided the epoxy-modified polymer hassufficient additional properties such that the desired film forming,phase segregated, surface adhesion, and microphase orienting propertiesof the resulting film are not significantly adversely affected. In anembodiment, the epoxy-containing polymer is prepared fromepoxy-containing monomers having a radically polymerizable carbon-carbondouble bond. Useful monomers comprise epoxy-containing (meth)acrylatemonomers having a C₃₋₃₀ epoxy-containing group, C₄₋₃₀ epoxy-containingolefinic monomers, or a combination comprising at least one of theforegoing epoxy-containing monomers. In a specific embodiment, theepoxy-containing polymer comprises radically polymerizedepoxy-containing monomers selected from the group consisting of glycidyl(meth)acrylate, 2,3-epoxycyclohexyl (meth)acrylate,(2,3-epoxycyclohexyl)methyl (meth)acrylate, 5,6-epoxynorbornene(meth)acrylate, epoxydicyclopentadienyl (meth)acrylate, and combinationscomprising at least one of the foregoing. A preferred monomer isepoxydicyclopentadienyl (meth)acrylate. Herein, where “(meth)acrylate”is used, either an acrylate or methacrylate is contemplated unlessotherwise specified.

The epoxy-containing polymer can also be a copolymer further comprisingan additional monomer in addition to the epoxy-containing monomer. In anembodiment, the additional monomer comprises a (meth)acrylate monomerderived from a C₁₋₃₀ alcohol, a C₂₋₃₀ olefinic monomer, or a combinationcomprising at least one of the foregoing additional monomers. In aspecific embodiment, the additional monomer is methyl (meth)acrylate,ethyl (meth)acrylate, butyl (meth)acrylate, hexyl (meth)acrylate,cyclohexyl (meth)acrylate, benzyl (meth)acrylate, ethylcyclopentyl(meth)acrylate, methylcyclopentyl (meth)acrylate, dicyclopentyl(meth)acrylate, 2-hydroxy ethyl (meth)acrylate, 2-hydroxy propyl(meth)acrylate, hydroxy adamantyl (meth)acrylate, adamantyl(meth)acrylate, methyladamantyl (meth)acrylate, ethyladamantyl(meth)acrylate, phenyladamantyl (meth)acrylate, hydroxyadamantyl(meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate,styrene, 4-methyl styrene, α-methyl styrene, 4-hydroxy styrene,4-acetoxy styrene, ethylene, propylene, 1-butene, 1,3-butadiene, vinylacetate, dihydropyran, norbornene, maleic anhydride, or a combinationcomprising at least one of the foregoing additional monomers.

In an exemplary embodiment, a useful epoxy-containing polymer ispoly(epoxydicyclopentadienyl methacrylate). In another exemplaryembodiment, an epoxy containing copolymer useful herein ispoly(styrene-ran-epoxydicyclopentadienyl methacrylate), a randomcopolymer of styrene and expoxydicyclopentadienyl methacrylate.

The epoxy-containing polymer desirably has a molecular weight andpolydispersity amenable to processing as disclosed herein, includingcasting, and such that the phase segregation is not significantlyadversely affected. In an embodiment, the epoxy containing polymer has anumber averaged molecular weight (Mn) of 1,000 to 198,000. In anembodiment, the epoxy-containing polymer can have a polydispersity(Mw/Mn) of 1.01 to 4. Molecular weight, both Mw and Mn, can bedetermined by any suitable method used in the art, and is generallydetermined by gel permeation chromatography using a universalcalibration method, calibrated to polystyrene standards.

The film-forming composition for use in the method comprises a blockcopolymer as a block copolymer assembly component. The block copolymercomprises blocks comprising one or more monomers, such that at least twoblocks in the block copolymer are compositionally, structurally, or bothcompositionally and structurally non-identical. The blocks themselvescan be homopolymers, or random or alternating copolymers. Differentkinds of block copolymers can be used in the composition, including anamphiphilic organic block copolymer, amphiphilic inorganic blockcopolymer, organic diblock copolymer, organic multiblock copolymer,inorganic-containing diblock copolymer, inorganic-containing multiblockcopolymer, linear block copolymer, star block copolymer, dendritic blockcopolymer, hyperbranched block copolymer, graft block copolymer, or acombination comprising at least one of the foregoing block copolymers.Suitable inorganic constituents of the inorganic-containing polymers,monomers, molecules, and additives include, for example, those based onsilicon, germanium, iron, titanium, aluminum, or the like. Exemplarysilicon- and germanium-containing monomers and polymers can includethose disclosed by H. Ito in “Chemical Amplification Resists forMicrolithography” Adv. Polym. Sci., vol. 172, pp. 37-245 (2005);exemplary metal containing monomers and polymers include those disclosedby Ian Manners in “Synthetic metal-containing polymers”, Wiley-VCH,2004; exemplary silicon-containing molecules and additives such asorganosilicates include those disclosed by E. M. Freer, L. E. Krupp, W.D. Hinsberg, P. M. Rice, J. L. Hedrick, J. N. Cha, R. D. Miller, and H.C. Kim in “Oriented mesoporous organosilicate thin films”, Nano Letters,vol. 5, 2014 (2005); and exemplary metal-containing molecules andadditives include those disclosed by Jinan Chai, Dong Wang, XiangningFan, and Jillian M. Buriak, “Assembly of aligned linear metallicpatterns on silicon”, Nature Nanotechnology, vol. 2, p. 500, (2007).

The blocks of the block copolymer can be any appropriatemicrodomain-forming block that can be copolymerized with another,dissimilar block. Blocks can be derived from different polymerizablemonomers, where the blocks can include but are not limited to:polyolefins including polydienes, poly(alkylene oxides) (sometimesreferred to as polyethers); poly((meth)acrylates), polystyrenes,polyesters, polyorganosiloxanes, polyorganogermanes, and the like. Itwill be understood that these blocks are exemplary and should not beconsidered as limiting.

In an embodiment, the blocks in the block copolymer comprise monomersselected from C₂₋₃₀ olefinic monomers, C₁₋₃₀ (meth)acrylate monomers,silicon monomers, germanium monomers, or a combination comprising atleast one of the foregoing monomers. In a specific embodiment, exemplaryC₂₋₃₀ olefinic monomers for use in the blocks include, ethylene,propylene, 1-butene, 1,3-butadiene, vinyl acetate, dihydropyran,norbornene, maleic anhydride, styrene, 4-hydroxy styrene, 4-acetoxystyrene, 4-methylstyrene, or α-methylstyrene; and the (meth)acrylatemonomers derived from C₁₋₃₀ alcohols can include methyl (meth)acrylate,ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate,n-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl(meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate,n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl(meth)acrylate, or hydroxyethyl (meth)acrylate. Exemplary blocks whichare homopolymers can include blocks prepared using styrene, i.e.,polystyrene, or (meth)acrylate homopolymeric blocks such aspoly(methylmethacrylate); exemplary random blocks include, for example,blocks of styrene and methyl methacrylate, e.g., poly(styrene-ran-methylmethacrylate), randomly copolymerized; and alternating copolymer blockscan include blocks of styrene and maleic anhydride which is known toform a styrene-maleic anhydride dimer repeating structure due to theinability of maleic anhydride to homopolymerize under most conditions,e.g., poly(styrene-alt-maleic anhydride). It will be understood thatsuch blocks are exemplary and should not be considered to be limitedthereto.

Exemplary block copolymer assembly components that are contemplated foruse in the present method also include a combination comprising at leastone block copolymer. The block copolymer can be di-block copolymer aswell as multi-block copolymer. Exemplary di-block copolymers includepoly(styrene-b-vinyl pyridine), poly(styrene-b-butadiene),poly(styrene-b-isoprene), poly(styrene-b-methyl methacrylate),poly(styrene-b-alkenyl aromatics), poly(isoprene-b-ethylene oxide),poly(styrene-b-(ethylene-propylene)), poly(ethyleneoxide-b-caprolactone), poly(butadiene-b-ethylene oxide),poly(styrene-b-t-butyl (meth)acrylate), poly(methylmethacrylate-b-t-butyl methacrylate), poly(ethylene oxide-b-propyleneoxide), poly(styrene-b-tetrahydrofuran), poly((styrene-alt-maleicanhydride)-b-styrene), poly(styrene-b-dimethylsiloxane), andpoly(styrene-b-dimethylgermanium oxide). Exemplary tri-block copolymersinclude poly(styrene-b-methyl methacrylate-b-styrene), poly(methylmethacrylate-b-styrene-b-methyl methacrylate), poly((styrene-alt-maleicanhydride)-b-styrene-b-methyl methacrylate),poly(styrene-b-dimethylsiloxane-b-styrene), and poly (ethyleneoxide-b-isoprene-b-styrene). An exemplary multi-block copolymer ispoly(styrene-b-methyl methacrylate)_(n), where n is greater than 1. Itwill be understood that the foregoing exemplary block copolymers areonly intended to be illustrative and should not be considered as limitedthereto.

The block copolymer can desirably have an overall molecular weight andpolydispersity amenable to the film forming steps disclosed herein, suchthat formation of domains in the block copolymer assembly can proceedwithout adversely affecting the segregation of the epoxy-containingpolymer from the block copolymer, and vice versa. In an embodiment, theblock copolymer has a number averaged molecular weight (Mn) of 1,000 to200,000 g/mol. Molecular weight, both Mw and Mn, can be determined by,for example, gel permeation chromatography using a universal calibrationmethod, calibrated to polystyrene standards.

The solvent in the film-forming composition can be a single solvent ormultiple solvent system in which each component is selected to provideoptimal solvent properties for both solubilizing the components in thefilm-forming composition, and to provide optimal film forming propertiesfor the composition. Exemplary solvents include propylene glycol methylether acetate (PGMEA), ethyl lactate (EL), ethoxyethyl propionate (EEP),2-heptanone, cyclohexanone, gamma-butyrolactone (GBL), or a combinationcomprising at least one of the foregoing solvents.

It has been found, in an embodiment, that a combination of solventshaving different solvating properties, and different evaporation rates,can be effectively used to provide optimum control of the film-formingprocess, including both the segregation of the orientation controlcomponents from the block copolymer assembly components, and theconcurrent formation of microphase-separated domains due to control ofthe different rates of desolvation, deposition and assembly of thesecomponents on the surface of the substrate. Specifically, for selectivedeposition, the orientation control component(s) is advantageouslyslightly less soluble in the solvent than is the block copolymerassembly component(s). This solubility difference and selectivity can befine tuned by use of a binary, ternary, or multi-component solvent. Inan exemplary embodiment, a combination of solvents that is useful forfilm forming control is PGMEA and GBL. In a specific embodiment, theweight percentage ratio of PGMEA to GBL can be from 99.9:0.1 to 50:50,based on the combined weight of the solvents. In a specific exemplaryembodiment, a 90:10 ratio (w/w) of PGMEA and GBL is useful as a solvent.

The film forming composition can further comprise additional componentsto assist in forming either or both of the orientation control layer andthe block copolymer assembly, including: additional polymers, includinghomopolymers, random copolymers, crosslinkable polymers; additivesincluding surfactants, photoacid generators, thermal acid generators,quenchers, hardeners, cross-linkers, or chain extenders; or acombination comprising at least one of the foregoing; where one or moreof the additional components can, in the film forming step, co-assembleinto microphase-separated domains together with block copolymer to formthe block copolymer assembly.

Exemplary photoacid generators and thermal acid generators includeN-hydroxyphthalimide triflate, bis(4-t-butyl phenyl)iodonium triflate,bis(4-t-butyl phenyl)iodonium perfluoro-1-butanesulfonate, bis(4-t-butylphenyl)iodonium perfluoro-1-octanesulfonate, bis(phenyl)iodoniumhexafluoroantimonate, N-hydroxy-5-norbornene-2,3-dicarboximideperfluoro-1-butanesulfonate, or a combination comprising at least one ofthe foregoing acid generators.

It is contemplated that by the addition of additional components to thefilm-forming composition as disclosed above, different desirableproperties can be obtained in the microphase-oriented domains of theblock copolymer assembly layer. For example, the additional polymers oradditives can co-assemble in the microphase-separated domains to form acomposite microphase-separated domain, in which the properties of themicrophase-separated domains can be adjusted based on the relativeproperties of the additives. For example, additives such as polymersthat can adopt different conformations can be added, which can beremoved from block copolymer assembly by thermal processes, by selectiveetch processes, or by selective solubility using organic, aqueous, oraqueous acidic or basic media, alone or in conjunction with photolyticcontrast enhancement methods, subsequent to film forming. Such regionscould be made porous, with oriented pores. In other embodiments, theadditives incorporated into the microphase-separated domains can besufficiently compositionally dissimilar (e.g., can comprise metal ormetalloid atoms such as iron, titanium, silicon and/or germanium) so asto enhance etch resistance, or conversely to enhance etch selectivity(e.g., where the component has higher oxygen content than the domain andpossesses a relatively high Ohnishi parameter) in a microphase-separateddomain relative to adjacent microphase separated domains, or within themicrophase separated domains. Any and all such further applications andinteractions are contemplated within the disclosure presented herein.

The film-forming composition can, in an embodiment, include the blockcopolymer and the orientation control component in a weight ratio of1:0.01 to 0.01:1 (w/w) of block copolymer to orientation controlcomponent. The total solids content of the composition comprising theorientation control component, block copolymer, and any additives, is0.01 to 30 wt % based on the total weight of the composition.

A more detailed description of the method is described hereinbelow. Inthe method of orienting microphase-separated domains disclosed herein,forming the film having the oriented microphase-separated blockcopolymer assembly includes applying the composition to a surface of asubstrate, and forming a compositionally segregated film on the surfaceof the substrate from the composition. The orientation control componentand block copolymer, as discussed hereinabove, form the compositionallysegregated film on the surface of the substrate during the film formingprocess, wherein the orientation control component is enriched thesurface adjacent to the substrate, and the block copolymer assembly isenriched at the air-film interface. Such a segregated film can beapplied using any number of methods including spin-casting, dip-coating,doctor blading, spray dispense, or the like. In an embodiment, thecomposition is applied by a spin casting method, which comprisesdispensing the composition onto a surface of a substrate, such as forexample a silicon wafer, and spinning the substrate to distribute thecomposition over the surface of the substrate. The solvent generallyevaporates during spinning, leaving the film. Additional processing ofthe film can include baking the composition disposed on the substrate,using an oven or hot plate.

In an embodiment, a method of forming oriented microphase-separatedblock copolymer domains in a compositionally segregated film thuscomprises applying a composition comprising an orientation controlcomponent including a homopolymer or copolymer of epoxycyclopentadienyl(meth)acrylate, and a block copolymer assembly component comprising ablock copolymer having at least one block capable of forming lamellae orcylindrical block structures, to a surface of a substrate. Theorientation control component is segregated from the block copolymerupon forming a film from the composition, and the orientation controlcomponent has an affinity for the surface of a substrate greater thanthat of the block copolymer. The composition is applied by coating itover the surface of the substrate, and then it is baked. During filmforming, the orientation control component and block copolymer segregateto form a compositional gradient perpendicular to the plane of thesubstrate, and thereby form the segregated film on the surface of thesubstrate. Vertical segregation can occur during coating, baking,annealing where desired, or a combination of these. The orientationcontrol component is enriched at the surface of the segregated filmadjacent to the surface of the substrate, and the block copolymer isenriched at a surface of the compositionally segregated film oppositethe surface of the substrate.

The film forming can be accomplished by, in one embodiment,spin-casting. In an embodiment, where spin casting is used, spinning iscarried out at 500 to 10,000 rpm. The solvent is largely removed fromthe film by the spinning process, during which the film can segregate tosubstantially form the orientation control layer and themicrophase-separated domains in the block copolymer assembly. In afurther embodiment, baking is carried out at 80 to 300° C. for a time of30 seconds to 20 hours. Baking can be performed not only to removeresidual solvent from the segregated film, but can in an alternative orfurther embodiment, also induce microphase segregation and domainformation in the block copolymer assembly, or can induce verticalsegregation of the block copolymer assembly and orientation controlcomponents.

In an embodiment, the block copolymer film as prepared by the methodincludes microdomains which are cylindrical and oriented perpendicularto the plane of the substrate, or which are lamellar and orientedperpendicularly to plane of the substrate.

A one-step process can be carried out by forming a segregated film froma mixed solution of block copolymers, substrate-selective orientationcomponents, air-surface-active orientation components and optionaladditives. In this case, both interface properties of top and bottominterfaces of block copolymer film can be controlled and allowed togenerate a block copolymer film with preferred orientation. Multi-layeror multi-gradient film stacks containing oriented block copolymerregions can be generated by vertical segregation using this method. Inan embodiment, the composition further comprises an air-surface-activeorientation-control component. Inclusion of such a surface-air interfaceactive component provides an additional orientation control at the airinterface surface of the block copolymer enriched region.

By the nature of the phase segregation mechanism, this one-step methodis useful to generate preferred orientation of microdomains in a varietyof block copolymer films on a variety of substrates, providing theorientation control components preferentially segregate to the substrateinterface. For example, poly(styrene-ran-epoxydicyclopentadienyl(meth)acrylate) works as an orientation control component on a varietyof substrates including silicon, silicon dioxide, silicon nitride, andthe like. Other substrates such as those comprising metal surfaces suchas for example gold, aluminum, titanium, tungsten, and the like, orother surfaces including glasses, ceramics, composite surfaces, and thelike, could be made that work by tailoring the composition of theorientation control component(s) to be compatible with and provideorientation control properties when disposed on these other surfaces.For example, a composition comprising orientation control componentswith thiol groups and block copolymer assembly components can be coatedon a gold substrate in which the orientation control components (havingthiol groups) segregate preferentially to the gold substrate, and theblock copolymer assembly components segregate to the air-surface in aone-step, spin-then-bake method.

A topographical pattern is then formed in the overlying block copolymerassembly. For a film comprising the block copolymer assembly, amicrophase-separated domain can be selectively removed by a suitableprocess such as wet or dry etch, development, or solvent solubility, sothat one microphase-separated domain comprising one kind of block isselectively removed over another microphase-separated domain comprisinganother kind of block. Thus, in an embodiment, a microphase-separateddomain of the block copolymer (of the block copolymer assembly) isselectively removed to provide a topographical pattern. Thetopographical pattern can then be transferred to the substrate by asuitable subsequent etch process. In an embodiment, the topographicalpattern is generated by selectively etching a microphase-separateddomain having a higher Ohnishi number than the other microphaseseparated domain(s) by an oxygen plasma etch.

The method disclosed herein can be adapted to form a film stack formultilayer patterning schemes such as bilayer or trilayer patterningschemes. Bilayer patterning typically refers to patterning a film stackof a resist and a pattern transfer layer on the substrate. The filmstack for a bilayer patterning scheme can be prepared in two differentways. In a first method of making a bilayer film stack, a film oforiented domains of a block copolymer assembly comprising anetch-resistant component can be formed on a previously formed patterntransfer layer, where the orientation control components are disposedbetween the block copolymer assembly and the pattern transfer layer. Theetch-resistant block copolymer assembly can comprise either a blockcopolymer comprising a block of an etch-resistant material, such as forexample a polyorganosiloxane block, a polyorganogermanium block, or thelike; or can comprise a block copolymer and inorganic-containingcompounds or polymers which can co-assemble with the block copolymer toenrich selective microphase separated domains. After patterning, themicrophase-separated domain of the etch resistant block copolymerassembly is sufficiently resistant to etch processes used for patterntransfer by selectively etching the carbon-based underlayer(s) (i.e.,the orientation control components from the segregated method disclosedhereinabove, and the previously formed pattern transfer layer). In thisscheme, the thickness of the orientation control component regionbetween the etch-resistant block copolymer assembly and the patterntransfer layer can be relatively small compared to the thickness of theetch resistant block copolymer assembly, so that pattern transfer intothe underlying pattern transfer layer is facilitated.

In a second method of forming a bilayer film stack, the entire bilayerfilm stack can be formed in one step directly on a substrate using themethod disclosed herein by using an etch resistant block copolymerassembly with etch resistant component(s) as disclosed above (i.e., ablock copolymer comprising a block of an etch-resistant material, suchas a polyorganosiloxane or polyorganogermanium block, or the like; orwhere the block copolymer assembly comprises a block copolymer andinorganic-containing compounds or polymers which can selectivelyco-assemble with the block copolymer to form a microphase-separateddomain that contains the inorganic-containing components). In thisinstance, after patterning to form a topographical pattern by removingthe microphase-separated domains without silicon and/or germanium, thesilicon and/or germanium containing microphase-separated domain issufficiently resistant to an etch process that would provide an etchrate for the carbon-based underlayer, (i.e., the orientation controllayer comprising the orientation control components) that is greaterthan that of the etch resistant microphase-separated domains. In thisscheme, a larger proportion of the orientation control componentrelative to the block copolymer assembly component is incorporated intothe composition such that it can also serve as the pattern transferlayer.

Bilayer patterning systems typically have thin (less than 100 nm) etchresistant patterning layers (as derived from the block copolymerassembly), and typically have pattern transfer layers that can be 20 nmthick to about 2 μm thick, depending upon the requirements of theapplication. Where the first method of forming the etch resistant blockcopolymer assembly and orientation control layer on the pre-formedpattern transfer layer is used, the orientation control components arepresent in amounts such that the orientation control layer is thin (lessthan 100 nm). Where the second method of forming the etch resistantblock copolymer assembly having the orientation control layer doublingas the pattern transfer layer is used, the orientation control layer isrelatively thick (often greater than 100 nm).

The method disclosed herein can also be adapted to forming a pattern fortrilayer imaging. In a trilayer imaging method, the trilayer film stackcan be formed in successive steps directly on a substrate using themethod disclosed herein by first applying a pattern transfer layer to asurface of the substrate, followed by formation of a hardmask (e.g., aspin-on polyorganosiloxane glass, low-temperature oxide, or the like).The orientation control component layer and block copolymer assembly areformed on the surface of the hardmask, where the block copolymerassembly comprises a block copolymer having a block for patterning withan etch rate that is at least comparable to, or desirably less than, theetch rate of the orientation control layer. In this way, whenselectively etching through a microphase-separated domain of the blockcopolymer assembly and the underlying orientation control layer using apattern open etch to expose the hardmask, the integrity of the patterncan be optimally preserved. The resulting opened pattern has an etchrate lower than that of the hardmask, using for example a halogen etchfor pattern transfer into the hardmask. The block copolymer assembly canfurther comprise additives or polymers which can selectively co-assemblewith the block copolymer to form a microphase-separated domain and whichcan enhance the desired etch rate of the microphase-separated domainrelative to the orientation control components and/or hardmask. Patterntransfer from the patterned microphase-separated domains of the blockcopolymer assembly to the substrate can be accomplished by use ofsequential etch processes, comprising: opening the topographical patternin the block copolymer assembly using an oxygen plasma etch; furthertransferring the pattern to the orientation control layer by an separateunderlayer open etch if necessary; transferring the pattern from thepatterned block copolymer assembly/orientation control layer to thehardmask by a halogen etch process; transferring the pattern from thepatterned hardmask to the pattern transfer layer by an oxygen plasmaetch process; and transferring the pattern from the pattern transferlayer to the substrate by a suitable substrate etch process.

In this embodiment, the orientation control layer or region is desirablyas thin as possible, to ensure that the pattern transfers from thepatterned block copolymer assembly layer to the orientation controllayer, and then to the hardmask without loss of pattern integrity andprofile. In an embodiment, the orientation control layer is desirablyless than or equal to about 100 nm in thickness, though the thicknesscan vary depending on the required etch selectivity between the blockcopolymer assembly, and the orientation control components.

In another embodiment of a trilayer imaging scheme, the orientationcontrol layer can function as the hardmask, thereby obviating the needto deposit a separate hardmask. In this embodiment, the orientationcontrol components comprise inorganic materials such as silicon orgermanium, and are deposited using the method described herein on asurface of a pattern transfer layer disposed on a substrate, so that avertically segregated, etch resistant orientation control layer thatalso functions as a hardmask is formed during film forming as describedabove. The orientation control components can comprise a copolymerhaving inorganic etch-resistant blocks or grafts, such as for examplepolyorganosilane and/or polyorganogermanium blocks, or alternatively,they can include polymeric or monomeric additives containing inorganicmaterials such as polyorganosiloxane polymers that segregate from theblock copolymer assembly components during film forming to form anorientation control layer along with the other orientation controlcomponents. The orientation control layer so formed is etchable underhalogen etch (hardmask etch) conditions, but resistant to the oxygenplasma pattern open etch conditions for patterning the block copolymerassembly layer, and is resistant to pattern transfer etch conditions fortransferring the hardmask pattern to the pattern transfer layerunderlying the hardmask. The trilayer stack comprising the blockcopolymer assembly layer and etch resistant orientation control layerwhich serves this dual role as hardmask, are formed simultaneously andin one step on the surface of a pattern transfer layer that has beenpre-deposited on a substrate, thereby reducing the number of stepsrequired to form the trilayer imaging system. Pattern transfer from thepatterned microphase-separated domains of the block copolymer assemblylayer is accomplished by use of sequential etch processes, comprising:opening the pattern in the block copolymer assembly layer by an oxygenplasma etch process; transferring the pattern to the etch resistantorientation control/hardmask layer by a halogen etch process;transferring the pattern from the patterned hardmask to the patterntransfer layer by an oxygen etch process; and transferring the patternfrom the pattern transfer layer to the substrate by a suitable substrateetch process.

Articles can be prepared using the method described hereinabove. As oneexample, one or more aspects of the present invention can be included inan article of manufacture, e.g., one or more computer hardware productssuch as permanent or rewriteable data storage media such as hard disksreadable by a machine, employing, for instance, computer usable media.The media have embodied therein, for instance, computer readable programcode means for providing and facilitating the capabilities of thepresent invention. The article of manufacture can be included as a partof a computer system or sold separately. Also contemplated areapplications in semiconductor chips, particularly for preparing featureshaving regular intervals in such devices, including memory devices suchas ROM, RAM, PROM, flash, and other memory types; microprocessorsincluding those with memory cache, ASICs, and the like.

The flow diagrams of the figures depicted herein are just examples.There may be many variations to these diagrams or the steps (oroperations) described therein without departing from the spirit of theinvention. For instance, the steps may be performed in a differingorder, or steps may be added, deleted or modified. All of thesevariations are considered a part of the claimed invention.

The invention is further described with respect to the examples, below.

Example 1A

A mixed solution of lamellae-forming PS-b-PMMA and the orientationcontrol components poly(epoxydicyclopentadienyl methacrylate) andN-hydroxyphthalimide triflate (PIT) (FIG. 5A) in a weight ratio of2:1:0.1 (respectively) in a mixed solvent of PGMEA and GBL (9:1 w/w)with total solids of 3% was cast on a silicon substrate and then bakedat 200° C. for 1 min. AFM image (FIG. 3A) of the resulting film showsperpendicularly oriented lamellae. Compared to the PS-b-PMMA film onsilicon substrate without orientation control components where theorientation of block copolymer domains and film thickness are notwell-controlled (FIG. 1D), the PS-b-PMMA film cast from the mixedsolution of block copolymer and orientation control component providesperpendicularly oriented lamellae having a uniform thickness over entirearea of the substrate. A cross-sectional SEM image (FIG. 3B) of thePS-b-PMMA film cast from the mixed solution of block copolymer andorientation control component clearly shows a two-layer film with asharp boundary between the layers, and uniformity of thickness. Thebottom layer (i.e., “orientation control layer” in FIG. 3B) is a film ofthe orientation control component, the top layer (i.e., “PS lines” inFIG. 3B) provides PS line patterns from perpendicularly orientedPS-b-PMMA film where PMMA has been selectively removed from the blockcopolymer layer using acetic acid. It is clear that both PS and PMMAdomains are present at the interface between the block copolymer layerand orientation control layer.

Example 1B

Perpendicularly oriented cylindrical PS-b-PMMA is made using the samemethod and conditions as the perpendicularly oriented lamellae ofExample 1A. A solution of cylinder-forming PS-b-PMMA, the orientationcontrol component (poly(epoxydicyclopentadienyl methacrylate)) ofExample 1A, and PIT, present in a weight ratio of 2:1:0.1 respectivelyin a mixed solvent of PGMEA and GBL (9:1 w/w) with a total solids of 3%,was spin-cast and baked under the same conditions as lamella-formingPS-b-PMMA. An AFM image (FIG. 3C) shows perpendicular PMMA cylinders ina PS matrix on the top of orientation control layer (not shown in FIG.3C). The method demonstrates orientation control of the block copolymerby, as shown, uniform and regular distribution of the cylinder featuresacross the surface.

Example 2

Solutions of lamella forming PS-b-PMMA, an orientation controlcomponent, poly(styrene-ran-epoxydicyclopentadienyl methacrylate) (FIG.5B) and PIT in a mixed solvent of PGMEA and GBL (9:1 w/w) with totalsolids of 3% were spin-cast on silicon substrates and baked at 200° C.for 6 hrs. Perpendicularly orientated of PS-b-PMMA lamellae wereobserved to form over a wide compositional range of block copolymer andorientation control components (FIG. 4). In particular, the compositions81 wt % PS-b-PMMA (abbreviated as “BCP” in FIG. 4), 68 wt % PS-b-PMMA,48 wt % PS-b-PMMA, and 26 wt % PS-b-PMMA (based on the combined weightsof the PS-b-PMMA and the orientation control component(poly(epoxydicyclopentadienyl methacrylate)), each exhibited lamellaeformation. The utility of the wide compositional range allows theadjustment of relative thickness of block copolymer and orientationcontrol layer. These results also show the stability of the segregatedfilm after extended baking (6 hours).

While the preferred embodiment to the invention has been described, itwill be understood that those skilled in the art, both now and in thefuture, may make various improvements and enhancements which fall withinthe scope of the claims which follow. These claims should be construedto maintain the proper protection for the invention first described.

What is claimed is:
 1. A composition comprising: a block copolymerassembly component comprising a diblock copolymer or triblock copolymerof styrene and methyl methacrylate; an orientation control componentcomprising radically polymerized epoxy-containing monomers selected fromthe group consisting of 2,3-epoxycyclohexyl (meth)acrylate,(2,3-epoxycyclohexyl)methyl (meth)acrylate, 5,6-epoxynorbornene(meth)acrylate, epoxydicyclopentadienyl (meth)acrylate, and acombination comprising at least one of the foregoing; and a solvent inwhich both the orientation control component and block copolymerassembly component are soluble; wherein the orientation controlcomponent is configured to segregate from the block copolymer assemblycomponent upon forming a film from the composition and become enrichedat a surface of the substrate and induce the block copolymer domains toorient perpendicular to a plane of the substrate to form an orienteddomain pattern, wherein the orientation control component is segregatedfrom the block copolymer assembly component upon forming a film from thecomposition, and the orientation control component has an affinity for asurface of a substrate that is greater than the block copolymer assemblycomponent's affinity for the surface of the substrate, such that theorientation control component is enriched at the surface of thesubstrate upon forming the film.
 2. The composition of claim 1, whereinthe block copolymer assembly component is a PS-b-PMMA block copolymer.3. The composition of claim 1, wherein the orientation control componentfurther comprises an additional repeat unit.
 4. The composition of claim3, wherein the additional repeat unit is derived from a (meth)acrylatemonomer having a C₁₋₃₀ alkyl group, a C₂₋₃₀ olefinic monomer, or acombination comprising at least one of the foregoing repeat units. 5.The composition of claim 3, wherein the additional repeat unit isderived from methyl (meth) acrylate, ethyl (meth)acrylate, butyl(meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl(meth)acrylate, ethylcyclopentyl (meth)acrylate, methylcyclopentyl(meth)acrylate, dicyclopentyl (meth)acrylate, 2-hydroxy ethyl(meth)acrylate, 2-hydroxy propyl (meth)acrylate, hydroxy adamantyl(meth)acrylate, adamantyl (meth)acrylate, methyladamantyl(meth)acrylate, ethyladamantyl (meth)acrylate, phenyladamantyl(meth)acrylate, hydroxyadamantyl (meth)acrylate, isobornyl(meth)acrylate, benzyl (meth)acrylate, styrene, 4-methyl styrene,□-methyl styrene, 4-hydroxy styrene, 4-acetoxy styrene, ethylene,propylene, 1-butene, 1,3-butadiene, vinyl acetate, dihydropyran,norbornene, maleic anhydride, or a combination comprising at least oneof the foregoing additional monomers.
 6. The composition of claim 3,wherein the epoxy-containing polymer ispoly(styrene-ran-epoxydicyclopentadienyl methacrylate) orpoly(styrene-ran-methyl methacrylate-ran-epoxydicyclopentadienylmethacrylate).
 7. The composition of claim 1, wherein the compositioncomprises at least one additional component selected from the groupconsisting of: additional polymers comprising homopolymers, randomcopolymers, crosslinkable polymers, inorganic-containing polymers, or acombination comprising at least one of the foregoing; and additivescomprising inorganic-containing molecules, surfactants, photoacidgenerators, thermal acid generators, quenchers, hardeners,cross-linkers, chain extenders; or a combination comprising at least oneof the foregoing; wherein one or more of the additional componentsco-assemble with the block copolymer to form the block copolymerassembly component.
 8. A method of forming a block copolymer assemblycomprising oriented microphase-separated block copolymer domains in acompositionally vertically-segregated film comprising: applying acomposition to a substrate to form a single film, the compositioncomprising an orientation control component comprising radicallypolymerized epoxy-containing monomers selected from the group consistingof 2,3-epoxycyclohexyl (meth)acrylate, (2,3-epoxycyclohexyl)methyl(meth)acrylate, 5,6-epoxynorbornene (meth)acrylate,epoxydicyclopentadienyl (meth)acrylate, and a combination comprising atleast one of the foregoing, a block copolymer assembly componentcomprising a diblock copolymer or triblock copolymer of styrene andmethyl methacrylate; and a solvent in which both the orientation controlcomponent and block copolymer assembly component are soluble; annealingthe single film; wherein the orientation control component verticallysegregates from the block copolymer assembly component such that theorientation control component is enriched at an interface of the singlefilm and the substrate and the block copolymer assembly component islocated at an interface of the single film and air; and wherein thesegregated orientation control component induces the block copolymerdomains to orient perpendicular to a plane of the substrate to form anoriented domain pattern.
 9. The method of claim 8, further comprisingselectively removing a microphase-separated domain of the blockcopolymer assembly component to form a topographical pattern.
 10. Themethod of claim 8, wherein the pattern comprises a plurality ofcylindrical domains that are perpendicularly oriented to a plane of thesubstrate.
 11. The method of claim 8, wherein the pattern comprises aplurality of lamellar domains that are perpendicularly oriented to theplane of the substrate.
 12. The method of claim 8, wherein the blockcopolymer assembly component is a PS-b-PMMA block copolymer.
 13. Themethod of claim 8, wherein the orientation control component furthercomprises an additional reheat unit.
 14. The method of claim 8, whereinthe composition comprises at least one additional component selectedfrom the group consisting of: additional polymers comprisinghomopolymers, random copolymers, crosslinkable polymers,inorganic-containing polymers, or a combination comprising at least oneof the foregoing; and additives comprising inorganic-containingmolecules, surfactants, photoacid generators, thermal acid generators,quenchers, hardeners, cross-linkers, chain extenders; or a combinationcomprising at least one of the foregoing; wherein one or more of theadditional components co-assemble with the block copolymer to form theblock copolymer assembly component.
 15. The method of claim 9, furthercomprising transferring the topographical pattern into the underlyingsubstrate.